<http://schema.org/image_url>
"http://media.oregonlive.com/travel_impact/photo/gettysburgjpg-8525fc0b6ccd7c9a.jpg"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.oregonlive.com/travel/index.ssf/2012/06/gettysburg_on_horseback_brings.html>